First you have to pass it by the local Health Department or whatever town/county service that covers your area.

Then you have a lot of concrete to remove for the new drain lines to drain to the tank. If you are below your sewage line going out to the septic tank you will need a sewage ejector pump to get rid of the waste.

This really is beyond a DIY project in my humble opinion. If you need to ask someone talk to your building official first. Then find a plumber.

You can also check out your local library on how to books. There is way to much to guess at on where to vent and how things are height wise on this forum.

Check out some of the websites for macerating type toilets,etc, such as the "sani plus,"sanitary for all" , saniflo.com. for more info.
They will accomodate a toilet, basin, shower or tub, and are great for installing into a septic piping layout, especially a basement. the macerating toilet and tank may be slightly on the costly side (approx $800)the ease of piping and no time consuming digging up of floors etc is required. They can be installed anywhere in the home you want . I installed mine in my rural home several years ago for approx $900 and that included the toilet, macerating tank and the piping ,fittings etc . Obviously the fixtures such as the basin, shower, tub are an added cost. Once these fixtures are in place it takes less than a day to complete the hook up.
And besides being easy to install, the toilet and tank look very much the same as any other normal toilet and tank. And no 'permit' was necessary either.
Btw, these tanks are about the same size as your normal toilet tank, they sit on the floor(behind the toilet and can pump waste vertically up to 12 ft, and horizontally up to 100ft. which will take care of the majority of most basement septic layouts.